Dependence of susceptibility to carcinogenesis on species life span.

Abstract

The data presented show no direct correlation between spontaneous tumor incidence and (a) the life span of species, (b) the life span of different strains or stocks of the same species, and (c) the life span of certain populations of the same strain or stock. This conclusion is in conflict with the concept suggesting a summation effect of the events that cause malignant growth irrespective of aging per se, in the age-related increase in cancer incidence, and indicates an important role of age-related changes occurring in the organism in the realization of carcinogenic effect of endogenous and/or exogenous factors.